i drove RR sports, both supercharged and not, and either way... they just weren't doing it for me...
(i worked at a jaguar, range rover dealer)
i became very familiar with the CSI (customer satisfaction index) for all jaguars, range rovers, bmw's, bentley's, and audi's while working for this place>>>> Land Rover had some of the lowest numbers (bottom 5 of all car makers, within the first 3 months of ownership) while BMW held its place in the top 3 of all car manufacturers, within the first year of ownership.
We had a discovery 2 land rover a while back, and although it was awesome offroad, and drove great for the first ferw months, things began to fall apart, and we ended up trading it in for a Jeep cherokee (btw, you might want to check out the new Jeep SRT 8, that thing is a beast)

overall, if you could only choose between these vehicles, i would hands down choose the X5...
we have a 4.4i black on tan, and its awesome... we've had no complaints since we bought it over a year ago (other than the maintainence costs... but any of these vehicles will do that to ya)...
but at the end of the day, you should go with your gut and get what you guys think fits best